1. Field of the Invention
The present embodiments relates to methods, systems, and programs for controlling processing on the surface of the wafer during a semiconductor manufacturing operation.
2. Description of the Related Art
In semiconductor manufacturing, etching processes are commonly and repeatedly carried out. As is well known to those skilled in the art, there are two types of etching processes: wet etching and dry etching. One type of dry etching is plasma etching performed using an inductively coupled plasma etching apparatus.
Plasma contains various types of radicals, as well as positive and negative ions. The chemical reactions of the various radicals, positive ions, and negative ions are used to etch features, surfaces and materials of a wafer. During the etching process, a chamber coil performs a function analogous to that of a primary coil in a transformer, while the plasma performs a function analogous to that of a secondary coil in the transformer.
A potential cause for lack of uniformity is the distribution of gases in the chamber, which may result in varying particle densities across the surface of the wafer, causing different etching rates between the center and the edge of the wafer. Further, another potential cause for lack of uniformity is the uneven distribution of etch by-product in the chamber during operation.
It is in this context that embodiments arise.